Linear shaped charge

ABSTRACT

A lightweight linear shaped charge for explosive cutting and penetration of target, which includes a plastic linear housing in the form of a concave channel with an inverted &#34;V&#34; shaped metallic liner mounted within the concave channel. An explosive charge is shaped and held between the plastic housing and the metallic liner. Upon detonation of the explosive charge an explosive jet of the metallic liner is generated to cut and penetrate the target. Also, the plastic linear housing may be extended downward a short standoff distance of approximately 0.5 to 1 inch for optimum cutting and penetration of the target.

GOVERNMENTAL INTEREST

The invention described herein may be manufactured, used, and licensedby or for the Government for Governmental purposes without payment to usof any royalties thereon.

This application is a continuation of application Ser. No. 07/931,466,filed Aug. 20, 1992, now abandoned.

BACKGROUND OF THE INVENTION

The invention relates to a lightweight linear shaped charge used forexplosive cutting of a target. The invention uses a lightweight plastichousing enclosing a metallic inverted "V" shaped liner, with anexplosive charge between the plastic housing and the metallic liner.

DESCRIPTION OF THE PRIOR ART

Current commercial linear shaped charges used for explosive cutting aremanufactured by squeezing an explosive filled metal tube or pipe into a"V" shaped configuration. The resultant shaped charge is heavier inweight than it needs to be for achievement of target cuttingperformance, because of the heavy total metal encasement. Only thebottom "V" shaped portion of the metal case, between the explosive andthe target, is effectively used in the cutting process. The upperportion of the metal case does add confinement to the explosive, whichaids somewhat in the cutting performance, but this can be done byincreasing the amount of explosive with a much lower weight of theshaped charge. The upper portion of the metal case also creates hotmetal fragments which could pose hazards to personnel near the chargewhen it is fired. For most commercial applications, the unnecessaryadded weight and the hot metal fragments are not a concern. However,certain military applications, such as special operations forcedemolition missions, require that the shaped charge weight be minimizedto enable manportability and the ability to parachute with the shapedcharge. Also some military breaching operations, such as building entry,will require personnel to be in proximity to the charge when it is firedand the hot metal fragments must be minimized. The military needs forlightweight, low fragmentation linear shaped charges have beenidentified in the last few years. None of the commercial linear shapedcharges can meet the military's performance requirements.

SUMMARY OF THE INVENTION

The invention solves the above problems by replacing the heavy metalupper case with a lightweight plastic housing which encloses a metallicinverted "V" shaped liner, with an explosive charge between the plastichousing and the metallic liner. In addition the metallic liner isoptimized in terms of metal thickness and angles for maximum cuttingperformance. Also, the invention provides integral extensions from theplastic housing to make a standoff separation of the metallic liner fromthe target to ensure optimum metal jet formation and best performance.

The novel features of the invention, as well as the invention itself,both as to organization and operation, will best be understood from theaccompanying drawing, taken in conjunction with the followingdescription.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a partial side view of the lightweight linear shaped charge ofthe invention.

DETAILED DESCRIPTION

Referring to FIG. 1 it is seen that the preferred embodiment of theinvention includes a lightweight plastic housing generally referred toas 30. The plastic housing 30 has the configuration of an elongatedlinear channel with a flat top section 31 joined on each linear side ofthe top section 31 by two downwardly extending and outwardly angled arms32, 33. The plastic housing 30 is in the form of a concave channelformed by the top 31 and the arms 32, 33 with the concavity openingdownward toward a target 50. A metallic liner, generally designated as20, is mounted along the full length of the plastic housing 30 withinthe concave opening and attached along the interior length of eachopposing arm 32, 33. The metallic liner has an inverted "V" shape withthe opening of the "V" facing downward towards the target 50. Theplastic housing 30 and the metallic liner 20 form an enclosed space 10extending linearly between the plastic housing 30 and the metallic liner20. An explosive 11 is held within the hollow space 10. A detonatorholder 40 is connected to the plastic housing 30 at an intermediatelocation along the top 31. A detonator 41 is inserted within thedetonator holder 40. The operation of the linear shaped charge of theinvention is commenced by manually placing the plastic housing 30 withthe arms 32,33 extending downward and in contact with the target 50.Upon detonation of the detonator 41 the explosive 11 is actuated andresults in an explosive jet which is optimized on top of the inverted"V" of the metallic liner 20 and concentrated downward for penetrationand cutting of the target 50. By varying the thickness of the metallicliner 20 and by changing the angles of the inverted "V" of the metallicliner 20 the invention provides a wide range of explosive metallic jetsfor different target 50 penetration and cutting requirements. Inaddition, the invention provides integral legs 34,35 extending downwardfrom the opposing arms 32,33 respectively. These legs 34,35 provide astandoff distance distance in the optimum range of approximately 0.5 to1 inch from the target 50 so as to maximize the penetration and cuttingforces unleashed by the lightweight linear shaped charge. It can be seenthat the novel plastic housing 30 holds the metallic liner 20 and theexplosive 11 together at a designated standoff distance from the target50 for optimum jet formation to penetrate and cut the target 50. Thoseskilled in the art of linear shaped charges will utilize the Munroeffect in determining the variables of housing 30, liner 20, andexplosive 11 to be used for particular target 50 penetration andcutting. The explosive 11 effectively accelerates the metallic liner 20for penetration and cutting. The plastic housing 30 reduces the weightof the lightweight linear shaped charge of the invention as well asminimizing the fragment hazard of the former metal cases or pipes. Theabove novel features of the invention will enable a cutting performanceequal to current metal housing and pipe charges while weighing less thanone-half the weight thereof.

It is to be understood that the above description and the accompanyingdrawing are merely illustrative of the preferred embodiment of theinvention, and that no limitations are intended in limitation thereofother than as defined in the appended claims.

We claim:
 1. A lightweight linear shaped charge for explosive cuttingand penetration of a target, which comprises:a plastic linear housinghaving a flat top connected along its length to two opposing arms toform a hollow concave channel therebetween with the concavity openingdownward toward the target for cutting and penetration; a metallicliner, having an inverted "V" shape, mounted within the concave openingand attached along the interior length of each opposing arm, with thetop of said inverted "V" shape extending lengthwise along the interiorof said linear housing beneath said flat top and above the target, so asto form a hollow interior space between said metallic liner and saidplastic housing; an explosive charge shaped and held within said hollowinterior space between said metallic liner and said plastic housing; anda detonator holder connected to said plastic housing and holding adetonator therein for initiation of said explosive charge to make anexplosive jet of said metallic liner for cutting and penetration of thetarget.
 2. The lightweight linear shaped charge of claim 1, wherein eachof said opposing arms are integrally extended a short distance outwardand downward toward the target.
 3. The lightweight linear shaped chargeof claim 2, wherein the the extension of each of said opposing arms isfor a distance of approximately 0.5 to 1 inch.